Typewriting machine



April 26, 1932. w. A. DoBsoN TYPEWRITING MACHINE Filed June 19, 1929 2Sheets*Sheet /m/enfar t myV/,MM

April 2s, 1932. w. A. DOBSON 1,855,342

TYPEWRITING MACHINE Filed June 19, 1929 2 sheets-'sheet 2 WwW/K7 Y I,Alf/orne Patented Apr. 26, 1932 UNITE STTES PTENT @FFICE WILLIAM A.DOBSON, 0F IBRIDGEPORT, CONNECTICUT, ASSIGNOR TO 'UNDERWOOD ELLIOTTFISHER- CIVIIPANY, OF NEW YORK, N. Y., A CORPORATION 0F DELAWARE lTYPEWRITIN G MACHINE Application filed .Tune 19,

This invention relates to the automatic ribbon-reversing mechanism oftypewriting machines.

One of the aims-of the invention is to meet the requirements of portabletypewriter mechanism for simplicity, compactness, inexpensiveness,lightness and reliability. The

invention, however, is also applicable to typewriters of standard size.

It is a feature of the invention to employ simple means for continuingthe'longitudinal movement of the ribbon during the priming of theautomatic reverser, this being necessary because, if the ribbon shouldstand still while receiving repeated type-impressions, it would becomedepleted of ink at that spot, and a hole would soon wear in the ribbon.It is therefore an aim of the invention to employ means for graduallypriming the ribbon-reversing device, as the ribbon continues itsadvance, during a succession of type-key operations in any of thevarious methods known in this art, as for example, in the mannerdisclosed in the patent to Stickney 1,075,996, in'which a pawl, which isreciprocated by the key-strokes, co-operates with a ratchet-wheel togradually prime a ribbon-reversing cam.

A purpose of the invention is to provide a gradual priming means withoutthenecessity of using followers to rest upon the ribbon coiled upon thespools as in said Stickney Patent, for initiating movement of automaticreversing mechanism.

A portable machine is often set down with a thump,y on theback end,opposite the handle end, opposite the handle end. This is liable tocause the swinging arms or ribbon-guides carrying the pawls to swing androtate the ratchet-wheels thereby causing both the lefthand and theright-hand ratchet-wheels to be accidentally rotated into ribboli-reversing positions and lock the machine.

In order to overcome this difficulty, there is provided a connectionfrom the usual carriage-centering lock, to hold the pawl against anypossible faulty action when the cover of the machine is in position.Before putting the cover on the machine, the carriage is alwayscentered; a hook at the'side of the ma- 1929. Serial No. 372,063.

chine being lifted to catch in the carriage as theoperator releases itand moves it to the left. The lifting of this hook operates to swing alever to a point in back of the pawlcarrying arm, so that this armcannot be swung.

@ther features and advantages will hereinafter appear.

In the accompanying drawings,

Figure l isaJ fragmentary sectional view, front toV rear, through anUnderwood portable typewriting machine with my invention appliedthereto.

Figure 2 is a fragmentary sectional view through the mechanism foroperating the right-hand spool in a plane approximately at a right angleto Figure l, certain of the parts being shown in elevation.

Figure 3 is a fragmentary view of the reversing mechanism inperspective.

Figure i is a fragmentary view of the carriage-locking device `alsoshowing a retaining means for holding .the actuating lever for thereversing mechanism when the machine is to be transported.

Figure 5 is a plan view of the ribbon-spools with operating andreversing mechanism showing the left-hand spool being operated and theright-hand spool thrown out of operation.

Figure 6 is a fragmentary perspective view of the right-hand spool andassociated ribbon operating and reversing mechanism of this invention.

Figure 7 is a fragmentary perspective view of the reversing mechanism ofthis invention, showing the button on the ribbon engaging the leverwhich puts the reversing mechanism in condition for operation by themovement of the keys on the keyboard. The position of the parts is suchthat the reversing lever is just beingengaged by the cam.

Figure 8 is a fragmentary perspective view of the ribbon reversing andfeeding mechanism of this invention showing the parts in position wherethe reversal takes place.

Figure 9 is a fragmentary elevation, partly in section, of theribbon-reversing device showing-its attachment to the frame of amachine.

The invention embodied in this application is shown in the accompanyingdrawings as being attached to a portable typewriting machine, in whichkeys 10 are fastened on key-levers 11, pivoted at 12 on a frame 13.Type-bars 14 are operated by a bell-crank 15 with a slotted arm 16engaging a pin 17 on the key-levers 11.

Rear arm 18 of the bell-crank lever is connected by a link 19 to thelower end 20 of a type-bar 14 which is fulcrumed at 21. The type strikeson a platen 22 pivoted in a carriage 24 by means of a shaft 23. Thekeylever is normally pressed upward by a coilspring 25. A universal bar26 extends across the machine under the key-levers 11 and is operatedeach time a key is depressed, after which it is returned to its normalposition by a coil-spring 28. The universal bar is pivoted at 27 and islimited in its upward movement by a rod 29. The usual oscillator 30holds the ribbon 31 and moves it into and out of position as a key 10 isstruck and released. The ribbon 31 is wound on the usual spool 32. Anarm 47 attached to the universal-bar is connected by a link 46 to arocker-arm 44 which is pivoted on a shouldered screw minates at awrist-member 76 having a slot 77 embracing a wrist-pin 42 fastened in anoscillating member 41. This member 41 has a spring-operated pawl 40pivoted thereto and bent at right angles to the member 41 so as toengage the teeth of a ratchet-wheel 35 mounted on a pivot 33, on whichthe spool 32 is held by a screw-cap 34. This pawl 40 is pressed towardthe ratchet-wheel by the usual coilspring. It is operated by spring 28,which returns the universal-bar train, on the up stroke of the key.

A sleeve 37 is passed over the pivot 33 and secured in a housing 74which is made of rectangular tubing. This housing support-s all of theribbon-spool-operating mechanism and is secured to the shift frame 56SLof the typewriter by screws 78. The sleeve 37 has a cam-plate 36 rigidlyattached thereto.

Pivoted to the shift frame 56n is a detentawl 48 which engages the teethof the ratchet-wheel 35 and holds it so that its action cannot reverseby reason of the friction of the operating pawl 40.

The cam-plate 36 is interposed between the oscillating member 4l and theratchetwheel 35 in order to throw out the operating and detent pawls 40and 48 simultaneously. This cam-plate is shaped substantially as shownin Figure 5 of the drawings.

The sleeve 37 attached to the cam-plate 36 has amember 38 clamped to itslower end so that the two will operate together, and yet permitadjustment of one relative to the other so as to properly engage ordisengage the pawls from the ratchet-wheels when reversal of theribbon-mechanism is required. The member 38 has a rearwardly-disposed75, and terarm 39 which is in position to be engaged by avertically-disposed cam-surface 60 attached to a cam-plate 59.

A housing 56 of rectangular tubing is attached to the shift frame 56 ofthe machine by screws 57 and 58. Pivoted in this housing is a shaft 55on which is rigidly mounted the cam-plate 59 by means of a hub 93 andset-screw 61. Attached to the inner part of the housing and bearingagainst said hub iS a spring 62, which produces friction so as toprevent overthrow.

Attached to the outer end of the shaft 55, on the opposite side of thehousing from the cam-plate, is a ratchet-wheel 53. This ratchet-wheelhas teeth 52 cut regularly in the greater portion of its circumference,but at one point 54 there is a section removed to the depth of theteeth, forming a gap. The cam-plate 59 has one section of itscircumference formed with the laterally-deiiected cam-surface 6()through which the camming action is produced on the rear arm 39 of thelmember 38. The ratchet-wheel 53 is operated by a lever 49 and pawl 51which engages the teeth 52 of said wheel, and is held against the wheelby means of a coil-spring 50. The lever 49 is pivoted on the rockerarm44 and is prevented from overthrow during action by alaterally-extendinglip 79 on the end of the lever 49 and a lug 80 on the rocker-arm 44. Thelateral swing of the lever 49 is prevented by an upwardly-extending lug72.

Pivoted to the frame at the side of the ribbon-spool is an arm or lever63 held in place by and rotated on a shouldered screw 64. This arm orlever has an upwardly-extending portion 65 with a slot 66 for thepurpose of guiding the ribbon. The lever 63 is held normally in closeproximity to a spool-cup 81 by means of a coil-spring 73 fastened at oneend to the arm or lever and at its other end to the frame of themachine. Loosely pivoted to the middle section of this arm or lever on apin 68 is a dog or pawl 69 having its downwardly-bent end 7 O engagingwith the teeth of the ratchet-wheel 53. This pawl has adownwardly-extending lug 82 to prevent lateral swing of the same duringoperation.

By reference to Figure 1 it will be seen that the pin 68 allows freedomof movement of the pawl 69 so that it will engage the wheel by theaction of gravity.

From this description it will be seen that when the rocker-arm 44 movesbackward and forward, the pawl 51 engages with the teeth 52 of theratchet-wheel. and moves said wheel one notch for each action of atype-bar. This continues until the wheel has made one revolution andcomes to the cut-out sector 54 when the pawl 51 simply oscillates backand forth without producing any movement of the ratchet-wheel 53. Thecam-member is so s... .LUL

bei

vmechanism for the spools.

disposed on the shaft that when this is the case the camming action isready to begin upon a slight movement of the wheel so as to engage thepawl 51 with the rst tooth 1 52 in the ratchet-wheel 53. lt will be seenthat by the relative size of the parts, as shown in Figure 1 ofthedrawings, this camming action of the reversing mechanism is notcompleted until three or four keys have been struck. The power requiredfor the reversal of the mechanism is therefore very slight, and notnoticeable to the operator, which is very important in this type ofmachine.

In order to partially rotate this ratchetwheel 53, a mechanism isprovided to give the wheel an initial movement by the-continued movementof the ribbon. This is accomplished by fastening a button 67 near theend of the ribbon, which passes through the slot 66 in the end 65 of thelever 6,3, and as it is paid out from the spool the button engages saidend, pulling the lever away from the spool-cup, and by reason oi' theengagement of the pawl 69 with the teeth 52 of the ratchet-wheel 53, itgives the initial movement necessary upon operation of the neXt two orthree type-bars. The following typeactions complete the camming actionof the cam-plate 59, throwing the member 38 in a lateral direction,which, through a link 83, operates a similar mechanism on the oppositespool to throw it out of action and throw the operating mechanism onthis spool into action, which starts to rewind the ribbon on the spool,and the coil-spring 73 returns the lever or arm 63 to its normalposition ready for the next reversal action.

As is readily seen from Figure 5 of the drawings, cam-plates 36' onopposite spools are operated so as to alternately put them in effectiveor ineiicective position, thereby placing the operating pawls 40 oftheribbonmechanism on each spool alternately in and out of position todrive the ribbon-winding The principal operation or" the drive-pawlmechanism may be substantially the same as set forth in patentto Lee S.Burridge, deceased, 1,249,022, dated December 4, 1917.

The link 83 is made of still wire bent in a substantially U-shapedformto operatively connect the two members 38 of the reversing mechanism.The U-shape disposes the connecting link so it is housed within themachine and between the operating parts, whichV prevents interference ofthe necessary movements. To the end that the feed mechanism may bereversed, at any time desired, a forwardly-extending lever 84, pivotedat 85 on the front portion of the machine, has a rearwardly-extendingslotted arm 86 to engage the link 83. The forwardly-extending portion ofthe lever 84 passes through a segmental slot in the cover-plate 87 ofthe machine tf'i for the purpose of operating it readily Vfrom thefront. The construction and operation of this lever may be substantiallythe samey as set forth in the co-pending application of George H.Meyers, 282,303, led June 2, 1928 (now Patent No. 1,808,505, dated June2, 1931 The depression of a key 10 vibrates the universal bar 26, arm47, link 46, rocker-arm 44 and member 41, to draw the pawl 40 idly overthe teeth of one ratchet-wheel 35, and, upon the release of the key, thespring 28 will restore these parts and drive the pawl 40 to turn theratchet-wheel a ribbon-spoolt'eeding distance. At each successive actionof the keys the ribbon is further wound until itreaches near the end onthe spool opposite, whose mechanism is inoperative. At this time, thebutton or eyelet 67 on the ribbon 31 Vstrikes the upwardly-bent end 65of the lever 63 and at each successive action, the button pulls thislever further out and away from the spool-cup, dragging with it theratchet-wheel 53 by means of the pawl 69. Since this action issuliicient to bring the pawl 51 into engagement with the first tooth ofthe ratchet-wheel next to the notch 54 where it has been inefl'ectivelyoperating, the actionof the next type-bar starts to rotate this wheel 53and begins the camming action on the arm 39 of the reversing member 38.Upon each further successive action the cam pushes the lever furtheruntil finally the cam-plate 36 is thrown into position to render theoperating pawl 40 of the full ribbonspool ineilective, and at the sametime, by the action of the interposed link 83, the cam-plate whichprevents operation of the ribbon-feed mechanism on the other spool isthrown out of position and permits the pawls 40 and 48 to engage theirratchet-wheel 35, thus rewinding the ribbon on the empty spool. By thisaction the power required to produce the complete reversal is dividedbetween the down and the up stroke of the key and makes it imperceptibleto the operator, while at the same time there is no undue strain putupon the ribbon or any of the operating mechamsm.

In order to hold the arms or levers 63 in normal position for operationwhen the typewriting machine is tilted in a vertical position, the ends88 projecting beyond the fulcrum-screws 64 are slightly weighted, eitherby extending them as shown in Figures 4 and 5, or applying a weight inany other manner to produce the same result. Sulicient weight should beadded so that the action of gravity, together with the pull of thecoil-spring 7 3, will prevent the` lever 63 from being thrown out ofnormal position which would tend to set the reversing mechanism intooperation on both sides of the machine at the same time. This is likelyto happen when the typewriter is carried in acase, and is set downforcibly on the end opposite ioo the handle. In order to `positivelyhold the lever or arm 63 on the left-hand side of the machine, anadditional lever 89 is pivoted on the frame of the machine and is formedin the shape of a bell-crank, pivoted at 95, the upper arm 90 of Whichhas a forwardly-projecting lip to engage a lug 91 on the lever 63. Theother end 92 has a slot 96 cut in it in order to fit into the notch 97in the edge of a carriage-positioning lever 94, as shown in Figures 1and 4, and substantially such as shown in the patent to Campbell1,677,170 dated July 17, 1928, so that when the carriage is in positionfor carrying in a case, the lever is moved upward to engage the hook 98With the end 99 of the carriage 24 and hold said carriage, therebyautomatically engaging the forward end of the arm 90 With Vthe lug 91 onthe lever 63.

This mechanism just described Will prevent the levers 63 from beingthrown backward out of position if the typewriter is set down With a jarWhile being carried in a case, and consequently would prevent the leversfrom setting the reversing mechanism into operation, which might causeboth ribbon-Winding devices to operate at once and lock the machine orpossibly cause injury to the same.

It will be understood that While the mechanism has been shown in thisparticular case as applied to a portable typewriting machine, it can bereadily employed in connection with any other form of typewriter, addingmachine or any other allied device employing a continuous ribbon formaking records, by making certain simple modications such as anyordinary mechanic is capable of suggestmg.

It will be readily understood that the weighted ends 88 of the lever-sor arms 63 may be omitted if desired.

The carriage 24 runs on the usual ballbearings 100 and 101, driven bythe usual spring-drum 102.

The invention is not limited to the exact details of construction shownand described; and portions of the improvements may be used withoutothers.

Having thus described my invention, I claim:

1. In a ribbon-eed-reversing mechanism for typewriting machines, thecombination of a ribbon-spool, means for rotating the same from theaction of the type-bars, means for rendering said rotating meansineective, a reciprocating member oscillated at each typestroke, aratchet on said member, a ratchet- Wheel with an inoperative sectionmounted so as to be engaged by said ratchet, means brought into play bythe unwinding of the ribbon to move said ratchet-Wheel to an eectiveposition, and means operatedby said ratchet-Wheel to reverse theoperation of the spool-rotating means.

2. In a ribbon-feed-reversing mechanism, the combination of a spool,means for rotating the spool, means to render said rotating meansineffective, a ratchet-Wheel vvith several teeth removed to render thesame normally ineffective, means operated by the un- Winding of theribbon for putting the ratchet-Wheel in condition for operation, meansfor operating the ratchet-Wheel, and means connected with saidratchet-Wheel to reverse the operation of the spool-rotating means.

3. In a ribbon-eed-reversing mechanism, the combination of a spool,means for rotating the spool, mea-ns to render said rotating meansineffective, a ratchet-Wheel with several teeth removed to render thesame normally inetective, means operated by the un- Winding of theribbon for putting the ratchet-Wheel in condition for operation, meansfor operating the ratchet-Wheel, a cam-disk mounted coaxially with saidratchet-Wheel, and means operated by said disk for reversing theoperation of the spool-rotating means.

4. In a ribbon-eed-reversing mechanism, the combination of a spool,means for rotating the spool, means to render said rotating meansineffective, a ratchet-Wheel With several teeth removed to render thesame normally ineective, means operated by the un- Winding of the ribbonJfor putting the ratchet-Wheel in condition for operation, means foroperating the ratchet-Wheel, a cam-disk mounted coaXially With saidratchet-Wheel, and a lever operated by said cam-disk for reversing theoperation of the spool-rotating means.

5. In a ribbon-feed-reversing mechanism, the combination of a spool,operating means including a means for rotating the spool, means torender said spool-rotating means ineEective, a ratchet-Wheel with anotch Where the operating means becomes ineffective, means to operatesaid ratchet-Wheel, means operated by the unwinding of the ribbon forputting the ratchet-Wheel in condition for operation, and meansconnected With said ratchet-Wheel for reversing the spoolrotating means.

6. In a ribbon-eed-reversing mechanism, the combination of a spool,operating means including a means for rotating the spool, means torender said spool-rotating means ineffective, a ratchet-Wheel With anotch Where the operating means becomes ineffective, a pavvl connectedWith said operating means and engaging said ratchet-Wheel, meansoperated by the unwinding or' the ribbon to put the ratchet-Wheel incondition for operation, and means connected with said ratchet-Wheel forreversing the spool-rotating means.

7. In a ribbon-eed-reversing mechanism.v the combination of a spool,operating means including a means for rotating the spool, means torender said spool-rotating means ineiective, a ratchet-Wheel With anotch Where the operating means becomes ineffective, a paWl connectedWith said operating means and engaging said ratchet-Wheel, a leveroperated by the unwinding of the ribbon, a second paWl engaging theratchet- Wheel and connected to said lever for moving the ratchet-Wheelinto position for operation by the paWl connected to the operatingmeans, and means connected with said ratchet-Wheel for reversing thespool-rotating means.

8. In a ribbon-feed-reversing mechanism, the combination of a spool,operating means including a means for rotating the spool, means torender said spool-rotating means inedective, a ratchet-Wheel With anotch Where the operating means becomes ineffective, a paWl connectedwith said operating means and engaging said ratchet-Wheel, a leveroperated by the unwinding of the ribbon, a second paWl engaging theratchet- Wheel and connected to said lever for moving the ratchet-Wheelinto position for operation by the paWl connected to the operatingmeans, a cam operated by said ratchet-Wheel, and means operated by saidcam for reversing the operation of the spool-rotating means.

9L In a ribbon-feed-reversing mechanism, the combination of a spool,operating means including a means for rotating the spool, means torender said spool-rotating means ineffective, a ratchet-Wheel with anotch Where the operating means becomes ineective, a pawl connected withsaid operating means and engaging said ratchet-Wheel, a lever operatedby the unWinding of the ribbon, a second paWl engaging the ratchet-Wheel and connected to said lever for moving the ratchet-Wheel intoposition for operation by the paWl connected to the operating means, acam connected coaXially With said ratchet- Wheel, and means operated bysaid cam for reversing the operation of the spool-rotating means.

10. In a ribbon-feed-reversing mechanism, the combination of a spool,operating means including a means for rotating the spool, means torender said spool-rotating means ineective, a ratchet-Wheel With a notchWhere the operating means becomes ineffective, a pavvl connected Withsaid'operating means and engaging said ratchet-Wheel, a lever operatedby the unwinding of the ribbon, a second pawl loosely engaging theratchet-Wheel and connected to said lever for moving the ratchet-Wheelinto position for operation by the paWl connected to the operatingmeans, and means connected With said ratchet-Wheel for reversing thespool-rotating means.

11. In a ribbon-feed-reversing mechanism, the combination of a spool,operating means including a means for rotating the spool,

means to render said spool-rotating means ineffective, a ratchet-WheelWith a Vnotch Where the operating means becomes ineffestive, a shaft onWhich said ratchet-Wheel is mounted, a housing for supporting saidshaft, a cam mounted on said shaft androtated by the ratchet-Wheel,means for rotating said ratchet-Wheel, means operated by the unwindingof the ribbon for putting the ratchet-Wheel into condition foroperation, and means connected With'said ratchet-Wheel for reversing thespool-rotating means.

l2. In a ribbon-feed-reversing mechanism, the combination of a housingattached to the frame of a typewriting machine, a shaft mounted in saidhousing, a ratchet-Wheel With a notch in its periphery mountedon saidshaft, a cam mounted'rigidly on said shaft, an operating lever actuatedby the type-bars, a spring-pressed pa-Wl connected to said operatinglever and engaging said ratchet- Wheel, means operated by the unwindingof the ribbon to rotate the ratchet-Wheel into position for operation bythe pawl, and means operated by the cam for reversing the ribbonfeedingmechanism.

13. In a ribbon-feed-'reversing mechanism, the combination of a housingattached to the frame of a typewriting machine, a shaft mounted insaidhousing, a ratchet-Wheel with a notch in its periphery mounted onsaid shaft, a cam mounted rigidly on said shaft, an operating leveractuated by the type-bars, a spring-pressed paWl connected to saidoperating lever and engaging said ratchet-Wheel, a second paWl forengaging said ratchet-Wheel to move it into operative position, a leverto which said paWl is connected, and means operated by the unwinding ofthe ribbon for moving said lever.

141-. In a ribbon-feed-reversing mechanism, the combination of a housingto be attached to the frame of a typewriting machine, a shaft mounted insaid housing, a ratchet- Wheel With a notch in its periphery attached tosaid shaft, a cam-disk rigidly attached concentric to saidratchet-Wheel, an operating lever actuated by the type-bars, aspringpressed paWl connected to said operating lever and engaging thebottom of the ratchet- Wheel, a second paWl engaging the top of theratchet-Wheel, means operated by the un- Winding of the ribbon foractuating said second paWl to move the ratchet-Wheel in position foroperation by the operating lever, and means operated by said cam-diskfor reversing the ribbon-feeding mechanism.

l5. In a ribbon-feed-reversing mechanism for a typewriting machine, thecombination of a ribbon-spool, means for rotating said spool, means forrendering said rotating means ineffective, a reciprocating memberoscillated at each type-stroke, a ratchet-Wheel with an inoperativesection, a spring-pressed paWl on said reciprocating member and engagingsaid ratchet-wheel for its operation, a cam-disk mounted rigidly andcoaxially with said ratchet-wheel, means brought into play by theunwinding of the ribbon to move the ratchet-wheel into position foroperation, and

means operated by said cam-disk for reversingthe feed of the ribbon.

16. The combination of a ribbon-spool, a ratchet-wheel for operatingsaid saool, a reciprocating lever pivoted on the rame of a typewritingmachine, a spring-pressed pawl and detent pivoted on the one end of thearm for engaging the ratchet-wheel, a link, a bell-crank and a universalbar connected together for operating said lever, a housing fastened tothe frame of the machine, a shaft mounted in said housing, aratchet-wheel with an inoperative portion mounted on said shaft, aspring-pressed pawl pivotally mounted on the reciprocating lever andengaging the teeth of said last-named ratchet-wheel, a cam-disk rigidlymounted on the shaft, a lever pivotally mounted on the frame, aribbon-guide on the end of the last-named lever, a pawl loosely pivotedon said lever, means attached to the ribbon for moving said lever as itunwinds near the end, thus turning the last-named ratchet-wheel by meansof said pawl to an operative position when the pawl on the lower end ofthe reciprocating lever can engage the teeth of this ratchet-wheel, acam-surface attached rigidly to a hollow shaft mounted on the axis ofthe ribbon-spool, a reversing lever mounted rigidly on the other end ofthe hollow shaft, having an arm to engage the above-mentioned cam-diskto throw the cam-surface on the hollow shaft to inoperative position soas to render the pawl and detent on the ribbon-ratchet effective forwinding the ribbon, and means controlled by the unwinding of the ribbonfor moving the ratchet-wheel having the inoperative portion to operativeposition.

17. The combination of a pair of ribbonspools, a ratchet-wheel foroperating each spool, a step-by-step driving pawl for eachratchet-wheel, a detent-pawl for each ratchetwheel, a cam-surface foreach set of pawls which prevents their operation when thrown intooperative position, reversing levers and links connecting said cams tothrow the one out of operative position when the other is in operation,a second pair of cams working in a plane approximately at right anglesto the first set, a shaft for rotating each of said cams, alratchet-wheel with an inoperative portion fastened to each of saidshafts, two reciprocating arms pivoted on the frame of the machine foroperating the above-mentioned pawls, a universal bar, type-keys foroperating said universal bar, links connecting said bar and thereciprocating arms, springpressed pawls attached to said reciprocatingarms and held against said ratchet-wheels which have an inoperativeportion on their circumference, actuating levers, means for moving saidlevers by the unwinding of the ribbon from one of said spools, pawlsloosely attached to each of said actuating levers and engaging saidlast-named ratchet-wheels for giving them a partial rotation to engagethe pawls cn the reciprocating arms with the operative part of theratchet-wheels, camplates rigidly attached to said last-namedratchet-wheels, and a projecting arm on each of said reversing leversfor engaging said cam-plates.

18. In a ribbon-feed-reversing mechanism, the combination of a spool forwinding a ribbon, means for feeding said ribbon automatically bymovement of the keys, means for rendering said feeding means operativeor inoperative, a reversing device consisting of a ratchet-wheel havinga cutout-portion, a pawl co-operating with said ratchet-wheel to rotateit through means operated by movement of the keys, a cam rigidlyconnected with said ratchet-wheel, a reversing lever operated by saidcam, means connected with said reversing lever to make theribbon-feeding mechanism inoperative, mechanism operated by the movementof the ribbon to give said ratchet-wheel an initial movement so as toconnect it with the operating pawl, and means to retain said mechanismin position for operation when the typewriter is being handled.

19. In a ribbon-feed-reversing mechanism, the combination of spools forwinding a ribbon, means for feeding said ribbon automatically, means forrendering said feeding means inoperative, a reversing device consistingof ratchet-wheels having a cutout-portion in each, pawls co-operatingwith said ratchetwheels for operating the same, a cam rigidly connectedwith each of said ratchet-wheels, means for reversing the feedingmechanism for the ribbon operated by said cams, levers or arms engagedby an obstruction on the ribbon as it is being fed, springs forretaining said levers or arms in normal position against the action ofsaid ribbon, weighted projections extending beyond the fulcrum of saidlevers or arms, and pawls connected with the levers and engaging saidratchetwheels to give them an initial movement and place the wheels inposition for operation by the operating pawls.

20. In a ribbon-reversing mechanism for typewriting machines, thecombination of a pawl operated at every key-stroke, a ratchet wheelhaving a notched portion in which said pawl normally works idly, anauXiliaryvpawl operable by the ribbon when a spool becomes unwound, toimpartto said ratchet-wheel sufficient motion to enable the first pawlto engage and drive a tooth of the ratchet-wheel, and thereafter toeffect, step by step, a cycle of movement of the ratchet-wheel; andmeans controlled by said ratchet-wheel for effecting a reversal of thedirection of Winding of the ribbon.

2l. In a typevvriting machine having a ribbon-feed, the combination ofmeans to reverse the direction of ribbon-feed, including a key-actuableratchet-Wheel normally idle at the key-strokes, and means to enable theribbon to rotate said ratchet-Wheel into co-operative relation with thekeys, to enable the keys to actuate said reversing means and therebychange the direction of ribbon-feed.

22. In a typewriting machine having means for feeding a ribbonlongitudinally in either one of two directions, the combination of meansto automatically reverse either ribbon-feeding direction including akey-actuable ratchet-Wheel for each end of the ribbon, and normally idleat the key-strokes, and means to enable the ribbon to rotate eitherratchet-Wheel into co-operative relation With the keys, to enable thekeys to actuate a ratchet-Wheel and reverse the direction of aribbon-feed.

23. In a typewriting machine having a ribbon-Winding mechanism, thecombination of a drive-pawl moving at every type-stroke, a ratchetwheeloperable by said drive-pawl, said ratchet-wheel having a gap in whichsaid drive-pawl normally plays idly, and means brought into actionautomatically when one spool is full of ribbon, for starting saidratchet-Wheel so as to advance the gap past the paWl, whereby the latterdrives the ratchet-Wheel, and means operated by said ratchet- Wheel forreversing the direction of Winding of the ribbon.

WILLIAM A. DOBSON.

